Archive for March, 2008

The question that naturally arises from my last post, Batting 102, is: why all this focus on where the ball will land? To answer that, we turn to the mechanics of batting.

There is more to hitting a cricket ball than simply swinging the bat with your arms. Your body’s largest muscles are in your legs and torso, so hitting a cricket ball involves your whole body. The same applies in tennis – when an elite tennis player hits a forehand, 50% of the force comes from his leg muscles. In golf, it’s what David Leadbetter (coach of Nick Faldo) calls the “athletic swing” – the power comes from an active, rotating body, not just the biceps.

In cricket, the transfer of the batsman’s weight is essential to every cricket shot, either onto the front foot to send full-pitched balls back in the direction they came from, or onto the back foot to allow a free rotation of the body for horizontal bat shots.

For every ball that a batsman faces, he must make this crucial decision: forwards or backwards. You will often hear commentators noting that a batsman’s downfall was brought about by “being caught on the crease” i.e. moving neither forward nor back. And the decision is based solely on the length of the ball i.e. how far down the pitch it bounces. Weight transfer is also the movement that takes the most time to execute. Hence, it should be the batsman’s priority. We have answered the question posed at the start: the batsman’s first task is to predict where the ball will land in order to accurately inform the forwards vs. backwards decision.

Every youngster who takes up cricket is given this advice: “watch the ball right onto the bat”. It’s not that the advice is wrong – it just has the wrong emphasis. It is the first stages of the balls flight that contain the most important information for the batsman. The final 0.2 seconds are irrelevant. The important thing is to watch the ball right out of the bowler’s fingers. This is the point where the “quiet eye” should be focussed.

This isn’t a particularly revolutionary conclusion, as the following quotes demonstrate:

Justin Langer:

“The most important thing about batting is to see the ball released from the bowler’s hand … pick up the ball as early as possible, then you can work out the length of the ball.”

Bob Simpson (former Australian coach, on working with Steve Waugh in the early 1990’s):

“When Steve started watching the ball out of the bowler’s hand, he suddenly had an extra metre to pick up the line and length of the ball, giving him extra time to get himself in the right position to play the appropriate stroke. “

What is the relevance of all this to sports psychology? A key mental ability in cricket is the ability to concentrate, especially in high-pressure situations and over long periods of time. But what exactly is concentration? Sports psychologists define concentration simply as “what you attend to.” As Griffiths notes, “it is not a question of whether you are concentrating or not … The question becomes ‘What are you concentrating on?’”

We can isolate what a batsman should be concentrating on, the task he should be attending to. The batsman’s task is to watch the ball right out of the bowler’s fingers, to pick up the length as soon as possible in order to make a decisive forward vs. backward movement.

But as Griffiths notes, “most people who tell you to concentrate cannot tell you how to concentrate.” How do you direct and control your concentration? We’ll start to answer this question in my next post.

Introduction to Batting in Cricket: Mechanics, Visual Strategy and Psychology
Other posts in this series:

We saw in my last post, Batting 101, that for the first stages of a cricket ball’s flight toward the batsman, the batsman isn’t following the ball with his eyes. He is keeping his eyes still, allowing the ball to cross his field of vision, before flicking them quickly to the point on the pitch where he thinks the ball will bounce.

Why is this? The answer is related to how batsmen judge the speed of the ball. In baseball, where the ball is coming (almost) directly at the batter, batsmen use two factors to judge the ball’s speed: the ball appears bigger (known as image expansion) and the batter’s eyes see different things (binocular disparity) as the ball gets closer. The rate of change of these effects is related to the ball’s velocity.

But in cricket, the ball is not coming directly at the eye – it bounces. Land and McLeod conclude that image expansion and binocular disparity would be insufficient to allow the accuracy with which elite batsmen judge the balls flight. The evidence in support of this conclusion is that batsmen do not track the ball for most of the pre-bounce period.

Instead, batsmen rely on the change in the angular position of the ball – the angular velocity. To measure this most accurately, batsmen keep their eyes still, so that the brain doesn’t have to “factor out” the movement of the eye. An image of the ball in the centre of the batsman’s field of view is not needed. Once they can estimate the speed, and in particular the downward velocity of the ball, they can estimate where it will bounce.

This visual strategy is what Dr. Joan Vickers from the University of Calgary calls “the quiet eye”: a period of time when the eye is stable on a critical object or location prior to the body performing the movement. Elite volleyball players, for example, wait almost 0.4 seconds after the ball is served before taking their first step, while less skilled players have no quiet eye at all: they begin moving even before the ball was served, making it difficult to maintain gaze on the ball. In cricket, the gaze is fixed on the point where the bowler will release the ball. Here’s a short video on the quiet eye from Scientific American.

It is only after the bounce (or late in the trajectory if the ball bounces close to the batsman) that image expansion and binocular disparity become useful information for the batsman. Their use is primarily to gauge the amount of bounce – this is related to the hardness of the pitch (the coefficient of restitution, or “bounce coefficient”), which the batsman learns through experience, not an intuitive calculation.

How does this visual strategy relate to the mechanics of hitting the ball? Stay tuned for my next post!

Introduction to Batting in Cricket: Mechanics, Visual Strategy and Psychology
Other posts in this series:

This is the first post in a series titled “Introduction to Batting in Cricket: Mechanics, Visual Strategy and Psychology”. I refer the reader to the outstanding book “Modern Psychology for Cricket and Other Australian Sports” by Robert Griffiths (1999). In this area, I am known as an “instant expert” – I read one book and I think I’m a genius. I will try to do justice to Griffiths’ book.

I need to discuss the mechanics of batting before I can look at psychology. In particular, we’ll look at how batsmen watch the ball.

In recent years, scientists have studied how elite cricketers judge the flight of a cricket ball. In particular, in 2000 Mike Land and Peter McLeod, from the University of Sussex and Oxford respectively, presented a detailed study of batsmen’s eye movements when facing very fast bowling. Their conclusions are quite surprising:

“… [batsmen] monitor the moment when the ball is released, make a predictive saccade [a fast movement of the eye] to the place where they expect it to hit the ground, wait for it to bounce, and then follow the trajectory for a period of 100-200 ms after the bounce.”

Let’s break down the stages. Land and McLeod found that, for the first 0.14 seconds of the balls trajectory, elite batsmen do not follow the ball with their eyes. (We’re talking about a fast bowler here – the total time from bowler’s hand to bat is about 0.6 seconds). The eyes are stationary, fixed on the point of release, and the ball moves down through the field of vision.

The next step is called a saccade – the eyes move very rapidly to the point on the pitch where the batsman thinks the ball will bounce. There they wait until the ball arrives.

After the ball bounces, the batsman tracks the ball for the next 0.1-0.2 seconds, but not necessarily all the way onto the bat. The reason for this is quite simple: Land and McLeod note that it takes an elite batsman 0.2 seconds to adjust his shot on the basis of new information. Thus, the information gained by watching the ball in the last 0.2 seconds of its flight is useless – there isn’t enough time to incorporate that information into the trajectory of the bat. Against a fast bowler (total flight time of 0.6 seconds), this is a third of the total flight time.

Mark Waugh makes it look so easy

But how should a batsman use this information? What lessons can we take from this discovery? This will be the topic of my next post.

Introduction to Batting in Cricket: Mechanics, Visual Strategy and Psychology
Other posts in this series: